rc.rs

single_file_tests/rc.rs

@@ -1,15 +1,38 @@
 use std::rc::Rc;
 
-fn main() {
-    let a  = Rc::new(0);
-
-    println!("{}", Rc::strong_count(&a));
-    let b = a.clone();
-    println!("{}", Rc::strong_count(&a));
-    let c = Rc::clone(&a);
-    println!("{}", Rc::strong_count(&a));
-
-    println!("{}", a);
-    println!("{}", b);
-    println!("{}", c);
+enum List {
+    Cons(i32, Rc<List>),
+    Nil,
+}
+
+use List::{ Cons, Nil, };
+
+fn print_list(list: &List) {
+    match list {
+        Cons(i, list) => {
+            println!("i -> {}", i);
+            print_list(&list);
+        },
+        Nil => (),
+    }
+}
+
+fn print_list2(mut list: &List) {
+    while let Cons(i, next_list) = list {
+        println!("i --> {}", i);
+        list = next_list;
+    }
+}
+
+fn main() {
+    let a = Rc::new(Cons(5, Rc::new(Cons(10, Rc::new(Nil)))));
+    let b = Cons(3, Rc::clone(&a));
+    let c = Cons(4, a.clone());
+
+    println!("print a");
+    print_list(&a);
+    println!("print b");
+    print_list(&b);
+    println!("print c");
+    print_list2(&c);
 }